ed 5.9GHz for V2V and V2I communication for vehicle safety applications
that is highly compatible with the U.S.
DSRC WAVE band, allowing the usage of similar antennas and wireless
transceivers in the platform.
The IEEE 802.11p standard was designed on top of the ASTM E2213-033
standard, which is a predecessor on ve-hicle-based communication networks.
It includes the architecture for VAN to
enable vehicle safety and non-safety
transactions such as toll collection
and traffic mapping. The goal in IEEE
802.11p is providing a framework to incorporate VANs throughout a nation’s
road infrastructure with sufficient V2V
and V2I communication features de-ployable as needed.
A higher-layer standard, which IEEE
802.11p is based upon, is the IEEE
1609 standard46 providing ubiquitous
vehicular communication among different automobile vendors and manufacturers. IEEE 1609 includes a family
of standards for WAVE. It defines the
architecture, organization, management structure, communication model, security mechanisms and physical
access. These features, collectively,
facilitate secure V2V and V2I wireless
communication in a variety of applications including traffic management,
active safety services, or automated
tolling. IEEE 1609 includes a subset of
standards, each particularly designed
to address a specific purpose in WAVE:
IEEE P1609.1 is the resource manager that identifies the key components
of the WAVE system architecture. It defines the communication formats such
as command message and data storage
formats and resources used among all
nodes of the architecture. This standard also indicates that OBEs and mobile platforms are supported in WAVE.
IEEE P1609.2 addresses the security issues in WAVE by defining secure
message formats. Basically, this standard takes care of secure message
management by specifying how secure
messages are processed once they are
IEEE P1609.3 is the network pro-
tocol layer standard in WAVE that
also supports secure message data
exchange. In addition to defining net-
work and transport layer services such
as routing, this standard also provides
a substitute for IPv6 by defining WAVE
short messages. This is WAVE-specific,
and can be used by most applications.
Moreover, the Management Informa-
tion Base (MIB) for the WAVE protocol
stack is also defined in this standard.
User-Defined Protocols. While the IEEE
VAN standard has been recently released, user-defined protocols are
needed to allow researchers and industry work on various applications, prototypes, and products.
Modified 802.11. Vehicular networks
demand robust wireless connectivity
for high-speed mobile outdoor environments. The original IEEE 802.11
standard does not meet these requirements, and thus, there is a pressing
need for a modified version of this
standard for VAN applications. The
problems of 802.11 mainly include
mobility, multi-path propagation due
to reflection in non-line-of-sight conditions, RF Doppler effect, and low
network bandwidth of 2Mbps. 17 Security challenges such as incorporating
authentication features and encryp-tion/decryption methods are also of
concern. The IEEE 802.11p technology
should be deployed in VAN as complementary technology to WiFi, 3G, and
WiMAX to address the issues noted
here, and enable V2I and V2V for safety
and emergency communications.
Scalability of 802.11p. The current
MAC parameters of the IEEE 802.11p
protocol are not efficiently configured
for a potential large number of vehi-
cles. The efficiency, performance, and
throughput decrease as the number of
vehicles increases. 47 Therefore, central-
ized or distributed techniques that com-
pute/estimate the number of communi-
cating vehicles in a geographical area
should be taken into consideration.
Furthermore, in the current 802.11p
protocol, the number of collisions dra-
matically increases as the number of
vehicles increases. 10 On the other hand,
issues such as packet loss come into the
picture as the speed of vehicles increas-
es. 35 For all these reasons, advanced
techniques should be integrated within
the IEEE 802.11p standard to overcome
such scalability issues.
existing Wireless solutions
Cohda Wireless Ltd, a developer in
the area of safe vehicle and connected
vehicle designs ( www.cohdawireless.
com), has addressed the mobility and
outdoor Non-Line-Of-Sight (NLOS) issues due to long delay spread and multipath propagation by designing a radio
on Wi-Fi chipsets. Particularly, Cohda
wireless has implemented the MK2
WAVE-DSRC Radio, which is an IEEE
802.11p-compliant device suitable for
V2V and V2I communication in WAVE.
At present, Atheros ( www.atheros.
com) and Broadcom ( www.broadcom.
com) have, at least partial support for
802.11p. There are other device manufacturers that have developed 802.11p-
compliant systems (for example, www.
aradasystems.com and www.redpines-ignals.com). All these solutions suggest
that 802.11p is the front-runner for serious deployment in VAN.
Simultaneously in academia, researchers have devised smart adaptive
antennas and cooperative/cognitive radios for wireless connectivity in vehicular networks. 53
security and Privacy of Van
A number of security mechanisms
has been integrated within the IEEE
P1609.2 standard, 46 enabling security
and privacy features for vehicle-area-networks. These issues are of significant importance and should be devised
before VAN becomes fully operational.
Imagine how false or stolen data such
as driver behavior, vehicle functional
information, environmental hazards,
or road condition data could cause